Nam T. Tran, Gabriel Wallace, Michael Sobel, Benjamin W. Starnes, Thomas Hatsukami
Division of Vascular Surgery, University of Washington, Seattle, WA.
OBJECTIVES: With endovascular treatment of blunt thoracic aortic injury (BTAI), accurate measurement of the aortic luminal diameter (ALD) is critical for accurate endograft sizing, but this diameter may be dynamic and can change with the patient’s hemodynamic status. We hypothesized that intra-operative intravascular ultrasound (IVUS) measurement of ALD might be different than those obtained from pre-operative computer tomographic angiography (CTA) in patients with BTAI.
METHODS: In an IRB approved study, we retrospectively evaluated all patients with BTAI admitted from July 2007 to July 2011 with pre-operative CTA and intra-operative IVUS. Post-implant CTA measurements were included for comparison. CTA and IVUS images were reviewed at the level of the left subclavian artery in order to maintain consistency in ALD measurement. Differences in diameter were compared using paired Student’s t-test.
RESULTS: Sixteen patients with BTAI were identified with pre-operative CTA, intra-operative IVUS, and post-implant CTA. Mean age was 39±16 years (17-73) with 75% males and mean ISS of 41 (26-54). Mean time from initial CTA to IVUS was 28 hours (2-132). Overall, the IVUS measured mean ALD was significantly larger than that obtained with pre-operative CTA (+2.38 mm, p=0.004). The mean ALD was larger when measured on post-implant CTA as compared to the initial CTA measurement (+3.13 mm, p=0.0001). With the use of intra operative IVUS measurement, the mean theoretical endograft diameter would have been 2.4 mm larger (p=0.003).
CONCLUSIONS: The aortic luminal diameter of patients with BTAI is significantly smaller when measured on pre-operative CTA as compared to intra-operative IVUS and post-implant CTA measurement. This difference in ALD can translate to potential under sizing of endografts used in endovascular repair of the patients with BTAI. The use of intra-operative IVUS provides a more accurate measurement of the actual ALD and should be used for sizing at the time of endovascular repair of patients with BTAI.
AUTHOR DISCLOSURES: T. Hatsukami, Nothing to disclose; M. Sobel, Nothing to disclose; B. W. Starnes, Nothing to disclose; N. T. Tran, Nothing to disclose; G. Wallace, Nothing to disclose.
Posted April 2012